Co nanoparticles combined with nitrogen-doped graphitic carbon anchored on carbon fibers as a self-standing air electrode for flexible zinc–air batteries

Abstract

Although zinc–air batteries (ZABs) have been extensively studied due to their advantages, there is still room for improving flexible ZABs especially by identifying suitable self-standing flexible electrode materials. Here, flexible porous nanofibers embedded with Co nanoparticles and nitrogen-doped graphitic carbon (Co@NPCFs) have been synthesized to work as self-standing and binder-free electrodes in flexible ZABs. These unique nanofibers with nitrogen-doped graphitic carbon are beneficial for electron transport, oxygen capture and desorption of the OH⁻ ions. The Co@NPCFs could provide rich active sites and exhibit good catalytic activity for both the oxygen evolution reaction and the oxygen reduction reaction. The fabricated composites with a flexible self-standing network structure can be applied directly to flexible ZABs and contact well with gel electrolyte when bending the batteries. As a result, this strategy provides a good example of flexible self-standing electrodes for ZABs and can also be extended to other flexible electric energy storage devices.